Bathtub



FIG. 1 is a perspective view taken from the top, front and left side of a bathtub showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof; and

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a bathtub, as shown and described. 